Drill



Feb. 26, 1929.

P; J. DUFFY DRILL Filed March 1924 v ljatented- Feb. 26, 1929.

PATENT OFFICE.

rnrnn J. DUFFY, or nousrou, TEXAS. Y

Application filed March 4, 1924. Serial No. $6,761.

This invention relates. to new and useful improvements in a drill. I

rOne object of the invention resides in the provision of a drillparticularly designed .for use in drilling through soft formations, butwhich may also be used in drilling through rock or other hardformations,

Another object of the invention is to provide a drill of the characterdescribed which is of such construction and contour that it will drill acomparatively straight bore.

A further feature of the invention resides in the provision of a drillhaving a detachable pilot, and detachable side cutters which may bereadily renewed in case they become worn or broken.

A still further feature of the invention resides in the provision of adrill having a central spiralled conveyor, so that when the pilot isremoved a core will be formed, by the drill, and conveyed up into a corebarrel with which the drill is equipped. With the above and otherobjects in view, this invention has particular relation to certain novelfeatures of construction, operation and arrangement of parts, an exampleof which is given in this specification and illustrated in theaccompanying drawings, where- Figure 1 shows a plan view of the drill.

Figure 2 shows a bottom end view. 1 I

Figure 3 shows a vertical sectional view.

Figure 4: shows a perspective view of one of the side cutters.

Figure 5 shows a side view of the pilot bit.

Figure 6 shows a point view thereof;

Figure 7 shows a side view, partly in section, of a supplemental coreconveyor, which may be employed; and Fi re 8 is a plug adapted to bescrewed into t e drill head 1, in lieu of pipe 6. 1

Referring now more particularly to the drawings, wherein like numeralsof reference designate similar parts in each of the figures, the numeral1 designates the drillheadwhose upper end is slightly reduced andoutwardly threaded to receive the drill collar 2, by means of which thedrill is attached to the drill stem (not shown). The head, beneath saidcollar,

tapers slightly downwardly, or is of an inverted frusto-conical contour.The tapered part of the head has the outside vertical dovetailed grooves3, spaced a artthere-around. Side'cutters 4, 4 are fitte into theserespective grooves, the inner sides of the cutters. being dovetailed tofit into the grooves.

The sides of the grooves, and likewise the sides of the cutters arecontracted or converge downwardly and the cutters are fitted into thegrooves from the upper ends of the latterand wedge therein. The drillcollar 2 is then screwed onto the shank of the drill and its lower endabuts against the upper ends of the cutters and locks them againstdetachment.

The outer edgesof the cutters are extended forwardly, as at-5, andformed with sharp cutting, or reaming edges, which converge at theirlower ends and project some distance below the drill head. The cutters 4have their cutting edges serrated, the teeth of some of said cuttersbeing staggered with relation to the teeth of the other cutters.

Within the drill stem, and screwed into the upper end of the head, thereis a core barrel 6,

of any desired length-whose upper end may be closed in any preferredmanner to exclude water or foreign matter and prevent the same frommingling with the core. Aligned with the core barrel there is a verticalbore 7,

through the head, whose walls are .provided with a spiral 8, forming acore conveyor.

the bit progresses through the strata, the projecting lower ends of thecutters 4, 4' form a core which passes up into'the bore 7 and is caughtby the spiralled conveyer 8, and car-- ried on upwardly and finallydelivered into the barrel 6. The bore 7 is sli htly enlarged upwardly sothat the core'wi not bind, or become stuck therein.

. If a smaller core be desired, a supplemental core conveyer 9 may bescrewed down- 7 wardly into the bore 7. This conveyer 9 has a verticalbore provided with a. spiral 10,

drill rotates in progress of the work. The

bore 7 and the supplemental conveyor 9 are provided with keyways 7 9adapted to register when the conveyor 9 is screwed home and to receive akey to prevent the unscrewing of the conveyor 9.

The lower end of the supplemental conveyer 9 is toothed, so as to reducethe size of the core formed by the cutters 4, 4:, in order that thereduced core will enter the con veyer 9. p

When it is desired to use the device as a drill only, a pilot 12 isthreadedup into the lower internally threaded end 13, of the bore 7.lhis pilot will hold the drill centered and a straight bore will thus bemade. This pilot may be of any desired form. Preferably it issubstantially conical in shape, and provided with radiating cutters 14,as shown. The head has the usual water courses 15 to admit flushingwater to the cutting edges of the cutters.

As illustrated, the drill is shown with six detachable cutters, but itis to be noted that any desired number may be used, and these cuttersmay vary in width, so that different iizeg of bores may be drilled withthe same When the drill is usedfor takin a core,

particularly in deep drilling, it may e found,

desirable to reduce the bore and this maybe done by removing the cuttersaltogether. The bearing shoulders, behind the respective cutters areformed with sufiiciently sharp cutting edges to ream out the bore duringthis core taking process, or very narrow blades may be used, so as'toreduce the bore during the core taking process, to the desired diameter,

It may be further noted that when the drill is not being used as a coretaker the core barrel 6 may be removed from the drill head, and

a plug as 16 screwed inthe upper end of said moaeeo head in an obviousmanner which will greatly strengthen the drill shank and lessen theliability of its breaking of.

, It is to be further noted that the forward sides of the cutters 4, 4:decline rearwardly or are slightly spiralled relative to the head, sothat the cuttings will more readily travel up said declining sides andfaces and will not be so liable to congest against the cutters.

It is further to be noted that the cutting edges of the cutters may beinset with diamonds as illustrated in Figure 4, or said cutters may bemade of any other hard material desired.

What I claim is 1. A drill including a head, formed with a vertical borehaving its inner walls formed into a spiralled conveyor, andapproximately vertical side cutters carried by the head whose edgesrecede toward both ends thereof and, whose lower ends extend below thehead.

2./'In a drill, a head having a vertical bore formed into a spiralledconveyor and dove-- tailed side cutters carried by the head, and formedwith cutting edges which recede toward each end thereof.

In testimony whereof I have signed my name to this specification.

PETER J. DUFFY.

